<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Symbol内置属性</title>
</head>

<body>
    <script>
        class Person {
            static [Symbol.hasInstance](param) {
                console.log(param);
                console.log("我被用来检测类型了");
                return false;
            }
        }

        let o = {};

        console.log(o instanceof Person);

        const arr = [1, 2, 3];
        const arr2 = [4, 5, 6];
        // 合并数组：false数组不可展开，true可展开
        arr2[Symbol.isConcatSpreadable] = false;
        console.log(arr.concat(arr2));
    </script>
</body>

</html>